May 9 (Reuters) - Infant hospitalizations due to respiratory syncytial virus (RSV) infections in the United States dropped as much as 43% last year compared to previous years, following the widespread availability of preventative shots, federal data showed.

The U.S. Centers for Disease Control and Prevention in a report on Thursday said that hospitalizations related to RSV decreased by 28% and 43% across two large national databases, compared to pooled rates from 2018-2020.

Years from 2020 to 2023 were excluded from the study because the COVID-19 pandemic led to unusual RSV seasonality and circulation, the study authors said.

WHY IT'S IMPORTANT

The 2024-2025 season marked the first period of widespread availability of preventive shots against RSV, a virus that often results in cold-like symptoms but is a major cause of severe infection and death in infants and older adults.

Separately, CDC data showed a drop in the infant mortality rate in 2024, compared to the previous year.

Pfizer's PFE.N maternal vaccine, sold as Abrysvo, and Sanofi SASY.PA and AstraZeneca's AZN.L antibody shot, Beyfortus, are available in the United States to prevent RSV infection in infants.

BY THE NUMBERS

The largest estimated reductions in hospitalization rates occurred among infants aged up to 2 months, the CDC said.

The infant mortality rate in the United States, defined as the number of deaths of children under one year of age per 1,000 live births, dropped to 5.49 in 2024, down from 5.63 a year earlier, CDC data showed.

CONTEXT

The data suggest that the most severe RSV disease among infants up to seven months old is preventable, the CDC said, adding that it is important to protect infants, ideally within their first week of life, especially those born during the RSV season.

(Reporting by Mariam Sunny in Bengaluru; Editing by Mohammed Safi Shamsi)

((Mariam.ESunny@thomsonreuters.com;))